Rotary hydraulic press

ABSTRACT

A rotary hydraulic press comprising a rotatable support shaft, a plurality of work stations circumferentially spaced around the axis of the shaft and mounted to rotate with the shaft wherein each of the stations comprises a cylinder with an internal power piston. A first means supports a first tool on the cylinder, and a second means supports a second tool on the piston and between the cylinder and the first tool support means. The cylinder is driven in a rotary path by the shaft, and valve means selectively connect the upper side of the piston with a source of fluid under pressure as the station passes a selected position in its rotary movement.

United States Patent [191 Michelson et al.

1 1 Nov.5,11'974 ROTARY HYDRAULIC PRESS [73] Assignee: Gulf & Western'Manufacturing Company, Hastings, Mich,

22 Filed: Oct. 2, 1973 21 Appl. No.: 402,847

[52] US. Cl. 72/349, 72/453 [51] int. Cl B2ld 22/28 [58] Field of Search 72/349, 404, 453; 113/1 G, 1 13/7 [56] References Cited UNITED STATES PATENTS 2,175,746 10/1939 Darling 113/] G 3,446,167 5/1969 Armbruster et al. 113/7 3,478,563 11/1969 Bozek ..72/349 Primary Examiner-Richard .l. Herbst [5 7] ABSTRACT A rotary hydraulic press comprising a rotatable support shaft, a plurality of work stations circumferentially spaced around the axis of the shaft and mounted to rotate with the shaft wherein each of the stations comprises a cylinder with an internal power piston. A first means supports a first tool on the cylinder, and a second means supports a second tool on the piston and between the cylinder and the first tool support means. The cylinder is driven in a rotary path by the shaft, and valve means selectively connect the upper side of the piston with a source of fluid under pressure as the station passes a selected position in its rotary movement.

9 Claims, 4 Drawing Figures 5mmx 7 3,845,652 PAIENTEDIM v mm! a ROTARY HYDRAULIC PRESS This invention relates to the art of hydraulic presses and more particularly to a rotary hydraulic press for performing a variety of metal working operations.

The invention is particularly adapted for mass production of small metal parts, such as drawing brass blanks into cartridge cases and it will be described with particular reference thereto; however, it should be appreciated that the invention has much broader applications and may be used for a variety of metal working operations.

In the manufacture of cartridge cases, it is necessary to draw cartridge blanks into elongated tubular structures. This is done by forcing the blank through a series of sizing dies which successively reduce the outer thickness of the blank and, in turn, elongate the blank into a cylindrical shaped tube. It has been suggested to perform this operation in a stationary hydraulic press.

' Such a press required movement of the blank into the press and subsequent movement of the tube from the press. This required a substantial amount of time which seriously limited the production rate. To overcome this problem, it was suggested that the extrusion operation could be performed by a rotary press whereby the extrusion operation took place while the workpiece was being moved from an inlet position to an outlet position. This, theoretically, would increase the productivity of the forming operation since the forming operation and transfer step were being performed simultaneously. These rotary presses included a cam operator for generating the working forces. It was found that such a mechanism was not satifactory because of the extremely high forces which were generated between the cam and the roller arrangement used to impart reciprocal movement to the extrusion punch. To over- I come this difficulty, it was suggested that a hydraulic press could be used wherein a cylinder would be located in a fixed positon and the tools, i.e., the punch and dies, would move with the workpiece to the cylin-' der, where hydraulic forces would be exerted against the punch. This procedure resulted in a relatively low production because the tools had to be stopped'during the forming operation. If the speed of the operation were increased, the weight of the tool would cause an undue stress on the driving mechanism during starting and stopping at a rapid rate.

The present invention overcomes all of the disadvantages of prior attempts to rapidly extrude a cartridge casing while the casing and tools are maintained in a constant motion to prevent difficulties associated with inertia by starting and stopping the tools.

In accordance with the present invention, there is provided a rotary hydraulic press comprising, in combination: a support shaft; means for rotating the shaft about its axis; and, a plurality of work stations circumferentially spaced around the shaft axis and mounted to rotate with the shaft. Each of the work stations comprises a cylinder with an internal power piston, a first chamber on one side of the piston and a second chamber on the other side of the piston. There is also provided a first port means communicated with the first chamber, a second port means communicated with the second chamber. means for supporting a first tool on the cylinder, means for supporting a second tool on the piston and between the cylinder and the means for supporting the first tool, and means for fixedly connecting the cylinder onto the rotating shaft. In addition, there is provided valve means for selectively connecting the first port with a source of fluid under pressure wherein the valve meansincludes a generally stationary element having a two-ended port with one end of the port connected with the source of fluid under pressure and means for rotating the'first port means into and out of communication with the other end of the two-ended port whereby the. second tool is driven toward the first tool.

The primary object of the present invention is the provision of a rotary hydraulic press, which press includes means for rotating both the tools and power cylinders used for a forming operation as a unit during the actual metal forming operation.

Another object of the present invention is the provision of a rotary hydraulic press, which press uses relatively light-weight tool holding and power generating elements.

Yet another object of the present invention is the provision of a rotary hydraulic press, which press can be operated at a relatively high rate and does not require starting and stopping of the tools for loading and unloading workpieces.

These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings in which:

FIG. 1 is a partial side elevational view of the preferred embodiment of the present invention showing certain portions in cross-section;

FIG. 1A is a partial side elevational view showing the remainder of the structure of the present invention excluded from FIG. 1;

FIG. 2 is an enlarged cross sectional view taken generally along line 2-2 of FIG. 1A; and,

FIG. 3 is a schematic hydraulic diagram illustrating the operating characteristics of the embodiment of the invention illustrated in the previous figures.

Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same, the figures illustrate a rotary hydraulic press A for extruding brass blank B into an elongated casing C. As illustrated, the rotary press has vertically spaced, stationary support frames l0, 12 including vertically aligned journals or hubs l4, 16 adapted to support aligned bearings 20, 22. The press A includes a center driven structure comprising the lower shaft 30, upper shaft 32, intermediate support 34 having a plurality of generally flat angularly disposed sides 34a, and an upper valve hub 36 with similar flat sides 36a. Onto these flat sides are supported a plurality of angularly disposed, circumferentially spaced work stations 40, 42, only two of which are shown. These work stations are substantially identical; therefore, only station 40 will be described in detail, and this description will apply equally to the other work stations spaced around the center rotating structure.

Referring now in detail to work station 40, it includes a power cylinder 50 having port 52 communicated with a first chamber 54 and a port 60 communicated with a second chamber 62. Top mounting housing 64 secures the cylinder 50, by bolts 66, onto one side 36a of the valve hub 36. Bottom mounting housing of cylinder 50 is secured onto the upper portion of a tool support bracket 72. This tool support bracket is a unitary casting including a top plate 74, a back plate 76, which is bolted onto side 34a of housing 34, and vertically extending, spaced tool support ribs 80, 82. These ribs terminate in generally T-shaped lower shoulders 84, 86, respectively. Shoulders 84, 86 are used to support the lower tool module 90 including a housing 92 having upper T-shaped slots 94, 96. These slots are used to slide the tool module over the ends of the support ribs 80, 82 so that force is transmitted through these ribs from the cylinder supported on plate 74 to the housing 92.

Referring in more detail to the lower tool module 90, as best shown in FIG. 2, housing 92 includes an end cap 100. The tool module employs a blank receiving block 102 having an access opening 104, shown in FIG. 1A. Dies 110-120 are axially aligned within the housing 92 and are spaced along the axis of the tool module by a plurality of appropriate spacers 130-134. Although the tool module 90 is supported by ribs 80, 82 there is provided auxiliary transverse ports in the form of recesses in axially spaced support plates 136, 138.

The blank B is forced through the respective dies to extrude the same into elongated casing C. To accomplish this, an upper punch 140 is connected by a rod 142 and a coupling 144 with a rod 146 driven by a piston 148 reciprocally mounted within cylinder 50 and dividing the cylinder 50 into the two chambers 54, 62. Downward movement of the piston 148 by pressure in chamber 54 extrudes the blank B through the dies to form the casing C.

The hydraulic system for accomplishing this hydraulic forming operation will now be described. A valve unit 150, best shown in FIGS. 1 and 3, includes a stationary hub 152 having a pressure port 154 with an inlet 156 and an outlet 158. The outlet has an angular length to control the time during which pressure is applied to the piston 148. A supply of fluid under pressure, schematically represented as pump 160, directs pressurized fluid through ports 154 and 162 in hub 36 to the port 52 in work station 40. Stationary hub 152 also includes a sump port 170 having an inlet 172 and an outlet 174. In this case, the inlet has an angular length to control the time during which port 162 is communicated with an appropriate sump, schematically represented as sump 180. Hub 36 has an internal cylindrical bore 182 which coacts with outer cylindrical surface 184 of stationary valve hub 152. This structure allows rotary movement between the stationary and rotating hubs through bearings 190, 192.

In operation, the piston 148 is in its upward position and a blank 8 is positioned within receiving block 102. During this time, the internal structure of the press is rotated and carries the blank to a position where port 162 of the work station 40 commmunicates with angular outlet 158. At this time, pressure is introduced into -:hamber 54 which forces the punch 140 downwardly against the blank B. This extrudes the blank into a casing c which is forced from the bottom of tool module 90. During this operation, the work station 40 is rotated. Communication between port 162 and outlet 158 is then discontinued, and communication of port 162 with the inlet 172 is established. Chamber 54 is then connected to sump 180 which allows upward movement of the punch 140. This process is repeated without stopping the movement of the rotary press. In this manner, high production is accomplished without .equiring stopping and starting of the tool module 90.

In accordance with the invention, there is provided means for biasing the piston 148 in an upward direction so that it may return to the upper position when port 162 is communicated with sump 180. A spring could be used for this purpose; however, in accordance with an aspect of the present invention, a hydraulic system is incorporated for biasing the piston upwardly. ln accordance with this aspect, a single conduit 200 is communicated with each of the ports in the respective work stations. As one piston 148 is moved downwardly, the lower chamber 62 is reduced in volume. This forces fluid from this chamber into the conduit 200. This pressurized fluid can then be used to force piston 148 upwardly by pressurizing the chamber 62 of another work station. In accordance with the illustrated embodiment of this aspect of the invention, an accumulator 202 is connected to conduit 200 by conduit 204. The accumulator contains a volume of liquid in the return conduit 200 and also maintains this conduit under at least a minimum pressure.

Referring now to FIG. 1A, a blank retainer 210 is used to position the blank within the tool module. As the casing C exits from the tool module, it is deposited onto a rotating removal station 212 coacting with a casing retainer 214 to hold the casing in place until it can be subsequently removed from the rotary press. A variety of structures could be used to accomplish the input and output to the rotary press.

Having thus defined our invention, we claim:

1. A rotary hydraulic press comprising, in combination: a support shaft; means for rotating said shaft about its axis; a plurality of work stations circumferentially spaced around said axis and mounted to rotate with said shaft; each of said stations comprising a cylinder with an internal power piston, a first chamber on one side of said piston and a second chamber on the other side of said piston, a first port means communicated with said first chamber, a second port means communicated with said second chamber, means for supporting a first tool on said cylinder; means for supporting a second tool on said piston and between said cylinder and said means for supporting said first tool, and means for drivingly connecting said cylinder onto said shaft; and valve means for selectively connecting said first port with a source of fluid under pressure, said valve means including a generally stationary element having a two ended port with one end connected with said source and means for rotating said first port means into and out of communication with said other end of said two ended port whereby said second tool is driven toward said first tool.

2. A rotary hydraulic press as defined in claim 1 wherein said stationary element includes a second two ended port and means for connecting one end of said second two ended port to a low pressure sump and means for rotating said first port means into and out of communication with said other end of said second two ended port whereby said second tool may be forced away from said first tool; and means for forcing said second tool away from said first tool when said first port means is communicated with said other end of said second two ended port.

3. A rotary hydraulic press as defined in claim 2 wherein said forcing means includes a second source of fluid under pressure and conduit means for communicating said second source with said second port means.

4. A rotary hydraulic press as defined in claim 3 wherein said conduit means includes a single conduit and means for communicating said single conduit simultaneously to said second ports of said stations.

5. A rotary hydraulic press as defined in claim 1 including a single conduit; means for connecting said single conduit to a source of fluid under pressure; .and means for communicating said single conduit simultaneously to said second ports of said stations.

6. A rotary hydraulic press as defined in claim 1 wherein said cylinders have axes generally parallel to said axis of said shaft.

7. A rotary hydraulic press as defined in claim 1 including a tool module including a housing forming said securing said housing to said cylinder. 

1. A rotary hydraulic press comprising, in combination: a support shaft; means for rotating said shaft about its axis; a plurality of work stations circumferentially spaced around said axis and mounted to rotate with said shaft; each of said stations comprising a cylinder with an internal power piston, a first chamber on one side of said piston and a second chamber on the other side of said piston, a first port means communicated with said first chamber, a second port means communicated with said second chamber, means for supporting a first tool on said cylinder; means for supporting a second tool on said piston and between said cylinder and said means for supporting said first tool, and means for drivingly connecting said cylinder onto said shaft; and valve means for selectively connecting said first port with a source of fluid under pressure, said valve means including a generally stationary element having a two ended port with one end connected with said source and means for rotating said first port means into and out of communication with said other end of said two ended port whereby said second tool is driven toward said first tool.
 2. A rotary hydraulic press as defined in claim 1 wherein said stationary element includes a second two ended port and means for connecting one end of said second two ended port to a low pressure sump and means for rotating said first port means into and out of communication with said other end of said second two ended port whereby said second tool may be forced away from said first tool; and means for forcing said second tool away from said first tool when said first port means is communicated with said other end of said second two ended port.
 3. A rotary hydraulic press as defined in claim 2 wherein said forcing means includes a second source of fluid under pressure and conduit means for communicating said second source with said second port means.
 4. A rotary hydraulic press as defined in claim 3 wherein said conduit means includes a single conduit and means for communicating said single conduit simultaneously to said second ports of said stations.
 5. A rotary hydraulic press as defined in claim 1 including a single conduit; means for connecting said single conduit to a source of fluid under pressure; and means for communicating said single conduit simultaneously to said second ports of said stations.
 6. A rotary hydraulic press as defined in claim 1 wherein said cylinders have axes generally parallel to said axis of said shaft.
 7. A rotary hydraulic press as defined in claim 1 including a tool module including a housing forming said means for supporting said first tool onto said cylinder, said housing including first means for holding said first tool and second means for securing said housing onto said cylinder.
 8. A rotary hydraulic press as defined in claim 7 wherein said housing includes a third means for reciprocally receiving said second tool.
 9. A rotary hydraulic press as defined in claim 7 wherein said first means includes at least one first T-shaped element and a second T-shaped element on said cylinder coactable with said first T-shaped element for securing said housing to said cylinder. 